1. Field of the Invention
The present invention generally relates to semiconductor devices and methods for producing semiconductor devices, and particularly, to a package structure of a semiconductor device so a surface-mount type which makes a high-density mounting possible and a method for producing such a package structure of a semiconductor device. The size of the package is about the same as the size of a semiconductor chip (element) on which a plurality of bumps are provided over the entire surface thereof.
Recently, semiconductor chips have been highly integrated so that the size thereof may be reduced in accordance with a reduction in size of an electronic device such as a handy-phone. Accordingly, there are demands for a package for a semiconductor device having a size which is suitable for containing a size-reduced semiconductor device and for a method for producing such a package for a semiconductor device.
2. Description of the Related Art
FIG. 1 is a diagram showing a conventional flip-chip type semiconductor device. A flip-chip mounting technique is used to reduce the size of a semiconductor chip and mount it on a board.
In FIG. 1, the semiconductor device includes a semiconductor chip 101, a plurality of bumps 102 connected to respective electrodes formed on the semiconductor chip 101, a mounting board 103 on which a plurality of lands for mounting respective bumps 102 are provided, and a resin 104 for sealing the semiconductor chip 101 and the plurality of bumps 102.
As for the structure of the semiconductor device shown in FIG. 1, each of the electrodes formed on the surface of the semiconductor chip 101 is directly connected to the respective land on the mounting board 103 via the corresponding bump 102. Then, the resin 104 is inserted between the semiconductor chip 101 and the mounting board 103 in order to absorb the difference in thermal expansion coefficient therebetween and to protect the surface of the semiconductor chip 101 and the plurality of bumps 102.
In the flip-chip bonding shown in FIG. 1, it is necessary, as mentioned above, to insert the resin 104 between the semiconductor chip 101 and the mounting board 103 in order to prevent a destruction of the bumps 102 due to stress applied thereto which is caused by the difference in the thermal expansion coefficient between the semiconductor chip 101 and the mounting board 103 when heat is applied to the device after mounting. However, it is difficult to inject the resin therebetween without generating voids and a complicated filling process become necessary to avoid the generation of voids. Also, since the bumps 102 are hidden by the resin after mounting, it is difficult to examine the connection state of the bumps 102.
Moreover, since the bumps 102 are provided on the semiconductor chip 101, the number of steps in a wafer process is increased and hence the cost for producing the semiconductor device is also increased.